Iran shares the Persian Gulf’s gigantic South Pars/North Dome gas field with Qatar. The country is home to nearly 16% of the world’s natural gas reserves — just under one quadrillion cubic feet. The country also has the third-largest amount of oil in the world, with 136.2 billion barrels of proved reserves. This is more than 10% of the world’s oil. The country is having problems realizing the monetary value of its resources due to its estrangement from international markets, stemming from its refusal to abandon its nascent nuclear development program.

Prior to the addition of its oil sands deposits to its proved reserves total, Canada probably would not have even made this list. The oil sands added about 150 billion barrels to Canada’s total in 2009 and 2010. According to most recent estimates, the country now has 178.1 billion barrels, giving it an estimated 17.8% of total global reserves, the second highest behind Saudi Arabia. The country also mines a good deal of the world’s phosphate, even though its deposits of phosphate rock are not among the top 10 in the world. The country also has the second-largest proved reserves of uranium and the third-most available timber.

Saudi Arabia has nearly 20% of the world’s oil — the greatest share among all countries. In fact, all of the country’s resource value is derived from hydrocarbons — either oil or gas. The kingdom has the world’s fifth-largest amount of proved natural gas reserves. Because these resources are depleting, Saudi Arabia eventually will run out of them and lose its high standing on this list. However, this will not happen for several decades.

The U.S. has 31.2% of the world’s proved coal reserves. Worth an estimated $30 trillion, this is by far the most valuable supply of any nation on earth. There is also 750 million forested acres in the country, which are worth nearly $11 trillion. Timber and coal combined are worth roughly 89% of the country’s total natural resource value. The U.S. is also in the top five nations globally for copper, gold and natural gas.

Russia is the world’s richest country when it comes to natural resources. It leads all other nations in the size of both its natural gas and timber reserves. The country’s vast size is both a blessing and a curse since economical transportation for gas (pipelines) and for timber (railroads) are significantly costly to build. In addition to having such large gas and timber reserves, Russia has the world’s second-largest deposits of coal and the third-largest deposits of gold. Additionally, it has the second-largest estimated deposits of rare earth minerals, although none are currently being mined.